我需要一些幫助讓我的程序重複

Question

我開發了一個程序，用於檢查用戶輸入的字符串是否是迴文。這部分工作正常，但我希望程序再次啓動，如果用戶想輸入另一個字符串。我看過不同的論壇，並嘗試不同的循環，但我無法讓程序重複正確。我目前有一個do語句，我認爲問題在於調用main()，因爲它在netbeans中被標記。我不知道爲什麼。任何幫助或在正確的方向微調將不勝感激。

/* 
* This program checks to see if the user input is a palindrome. 
* white space and non alphanumeric characters will be ignored. 
*/ 
package firstsubroutines; 

/** 
* 
* @author anonymous 
*/ 

public class FirstSubroutines { 

    static String str; // global variable 
    static String reversed; // global variable 

/* 
* The subroutine strp accepts a string as an argument 
* and returns a string stripped of spaces and 
* non alphanumeric characters 
*/  
    static String strip(String str){ 
     str = str.replaceAll("[^a-zA-Z0-9]", ""); 
     str = str.toLowerCase(); 
     System.out.println("Stripped: " + str); 
     return str; 
    } // end of subroutine stripped 

/* 
* The subroutine reverse accepts a string as an argument 
* and returns a string in reverse order 
*/ 
    static String reverse(String str){ 
     int i; 
     reversed = ""; 
     for (i = str.length() - 1; i >= 0; i--) { 
      reversed = reversed + str.charAt(i); 
     } 
     System.out.println("Reversed: " + reversed); 
     return reversed; 
    } // end of subroutine reversed 

/* 
* This is the main progam where the subroutines 
* will be called 
*/ 
    public static void main(String[] args) { 
     String userInput; // The input by the user. 

     System.out.println("This program checks to see if the user's input is a palindrome."); 
     System.out.println("White space and non alphanumeric characters will be ignored."); 
     System.out.println(); 
     System.out.print("Please enter a string: "); 
     userInput = TextIO.getln(); // assigns the user input to a variable 

     // subroutine strip is called and an the value of 
     // the variable userInput is passed 
     str = strip(userInput); 

     // subroutine reverse is called and an the value of 
     // the variable str is passed 
     String rev = reverse(str); 

     // compares the two objects 
     if (str.equals(rev)) { 
      System.out.println("This IS a palindrome"); 
     } 
     else { 
      System.out.println("This NOT a palindrome"); 
     } // end of if statement 


     boolean toContinue; // True if user wants to play again. 
     do { 
      main(); 
      System.out.print("Do you want enter another string?: "); 
      toContinue = TextIO.getlnBoolean(); 
      } while (toContinue == true); 

    } // end main 

} // end class 

Answer 1

獨立的輸入處理邏輯，另一種方法：

private static void processString(){ 

     String userInput; // The input by the user. 

     System.out.println("This program checks to see if the user's input is a palindrome."); 
     System.out.println("White space and non alphanumeric characters will be ignored."); 
     System.out.println(); 
     System.out.print("Please enter a string: "); 
     userInput = TextIO.getln(); // assigns the user input to a variable 

     // subroutine strip is called and an the value of 
     // the variable userInput is passed 
     str = strip(userInput); 

     // subroutine reverse is called and an the value of 
     // the variable str is passed 
     String rev = reverse(str); 

     // compares the two objects 
     if (str.equals(rev)) { 
      System.out.println("This IS a palindrome"); 
     } 
     else { 
      System.out.println("This NOT a palindrome"); 
     } // end of if statement 


} 

然後只是把它從main在一個循環：

public static void main(String[] args) { 

     boolean toContinue = false; // True if user wants to play again. 
     do { 
      processString(); 
      System.out.print("Do you want enter another string?: "); 
      toContinue = TextIO.getlnBoolean(); 
      } 
     while (toContinue == true); 
} 

Answer 2

使用Scanner類：

Scanner sc = new Scanner(System.in); 

while (sc.hasNext()) { 
    String input = sc.next(); 
    // do something with input 
}